Coatings for resisting impact damage are known for protecting wood, metal, masonry, concrete, cement, and fiberglass, for example.
Polyurethane varnishes are known to protect wood, since they have some inherent flexibility (toughness, as distinct from hardness), allowing them to absorb impacts better without cracking. Moisture cure polyurethanes are known for protecting hardwood floors. A moisture cure polyurethane uses moisture in the air to cure and cross-link.
Moisture cure polyurethane (also called “moisture cured”, and “moisture curing”) with an acrylate polymer additive, such as a copolymer of butyl methacrylate and methyl methacrylate (BMA/MMA copolymer), is known for use as a durable coating for steel structures such as bridges.
Yet, there are technical challenges in applying a coating of moisture cure polyurethane with an acrylate polymer additive to a wood surface, due to problems with low chemical compatibility between the coating and typical wood surface finishes, such as the clear finish commonly found on wood drum sticks, thereby preventing good adhesion.
Additionally, strong impact resistance and abrasion resistance are required of the coating on the tip and shoulder area of wood drumsticks so that the impact-protective coating does not tend to chip off and break away as the drumstick is hit against the rims of drums and cymbals.